Display device

ABSTRACT

A display device is configured that the common electrode wiring layer is divided in a source wiring layer direction, the metal wiring layer is disposed above the source wiring layer at a position in contact with the upper part of the common electrode wiring layer, and the metal wiring layer is not disposed at a position where the common electrode wiring layer is divided. Alternatively, the metal wiring layer is not disposed at a position between the same colors as those at the division position of the common electrode wiring layer.

CLAIM OF PRIORITY

The present application claims priority from Japanese patent applicationJP2013-211293 filed on Oct. 8, 2013, the content of which is herebyincorporated by reference into this application.

BACKGROUND

The present invention relates to a display device, which is applicableto the display device with an in-cell type touch panel, for example.

Recently, the capacitive touch panel has been employed as the inputfunction installed in the liquid crystal display device for mobileusage, mainly of smartphones. Efforts have been made to promote thein-cell type capacitive touch panel by incorporating the function intothe liquid crystal display device. The common electrode with FFS (FringeField Switching) structure has been utilized for realizing theaforementioned in-cell type capacitive touch panel. The common electrodeas ITO (Indium Tin Oxide) is formed on the TFT (Thin Film Transistor)glass substrate, which serves as a driving electrode for the touchpanel. The detection electrode as ITO is formed on the back surface ofthe CF (Color Filter) glass substrate.

In reference to JP-A-2009-244958, the common electrode divided in thegate line direction is combined with the detection electrode divided inthe source line direction so as to provide the touch panel function. AsJP-A-2010-231773 and WO 2012/073792 disclose, the common electrode isdivided in the source line direction.

SUMMARY

The applicant of the present invention has found the problem asdescribed below, which is revealed when dividing the common electrodewiring layer in the source wiring layer direction.

If the common electrode wiring layer is divided in the gate wiring layerdirection, the metal wiring layer is disposed above the source wiringlayers in entirety at the position below a BM (Black Matrix), which isin contact with the common electrode wiring layer for reducing theresistance thereof. This makes it possible to prevent the color mixtureat viewing angle resulting from assembly displacement between the TFTglass substrate and the CF glass substrate. However, if the commonelectrode wiring layer is divided in the source wiring layer direction,it is not possible to dispose the metal wiring layer at the positionwhere the common electrode wiring layer is divided. This may cause thecolor mixture at viewing angle.

It is an object of the present invention to provide the display devicethat lessens the color mixture at viewing angle.

Any other problems and novel features will be clarified by thedescription of disclosure herein and the drawings.

Summary of the present invention will be described as below.

The display device is configured that the common electrode wiring layeris divided in the source wiring layer direction, and the metal wiringlayer is disposed above the source wiring layer at the part in contactwith the upper part of the common electrode wiring layer. The metalwiring layer is not disposed at the position where the common electrodewiring layer is divided. The metal wiring layer may be designed to bepositioned above the source wiring layer, but not to be disposed at theposition between the same colors as those at the divided position of thecommon electrode wiring layer.

The display device as described above is capable of lessening the colormixture at viewing angle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating structure of a liquid crystal displaydevice according to a first comparative example;

FIG. 2A is a view illustrating structure of a liquid crystal displaydevice according to a second comparative example;

FIG. 2B is a view representing color mixture which occurs on the liquidcrystal display device according to the second comparative example;

FIG. 3A is an explanatory view with respect to principle that the colormixture at viewing angle occurs upon assembly displacement;

FIG. 3B is an explanatory view with respect to principle that the colormixture at viewing angle occurs upon assembly displacement;

FIG. 3C is an explanatory view with respect to principle that the colormixture at viewing angle occurs upon assembly displacement;

FIG. 3D is an explanatory view with respect to principle that the colormixture at viewing angle occurs upon assembly displacement;

FIGS. 4A and 4B are views illustrating structure of a liquid crystaldisplay device according to a first embodiment;

FIGS. 5A to 5C are views illustrating structure of the TFT glasssubstrate according to the first embodiment;

FIG. 6A is a view illustrating structure of the liquid crystal displaydevice according to the first embodiment;

FIG. 6B is a view representing color mixture on a liquid crystal displaydevice according to a third comparative example;

FIG. 7A is a view illustrating structure of a liquid crystal displaydevice according to a third embodiment;

FIG. 7B is a view representing color mixture on the liquid crystaldisplay device according to the third embodiment;

FIG. 8 is a view illustrating structure of a liquid crystal displaydevice according to a first modified example;

FIG. 9A is a view illustrating structure of a liquid crystal displaydevice according to a fourth embodiment; and

FIG. 9B is a view representing color mixture on the liquid crystaldisplay device according to the fourth embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The problem of the color mixture at viewing angle, which has been foundby the applicant of the present invention will be described.

FIG. 1 is a view illustrating structure of the display device accordingto a first comparative example. The upper section of FIG. 1 is a planview illustrating a part of the liquid crystal display device, and thelower section is a sectional view taken along line A-A′ of the uppersection. A display device 11 according to the first comparative exampleincludes a TFT glass substrate 12, a CF glass substrate 13, and a liquidcrystal layer 21 interposed between the TFT glass substrate 12 and theCF glass substrate 13. A common electrode wiring layer 14 of the TFTglass substrate 12 is divided in the direction parallel to a gate wiringlayer (X direction) so that metal wiring layers 15 in connection withthe common electrode wiring layer 14 are disposed between the respectivesubpixels. A division region 20 (division position) between the dividedparts of the common electrode wiring layer 14 extends in the Xdirection, and is periodically arranged in the Y direction. The metalwiring layer 15 provides both the function as a light shielding layerfor preventing the color mixture at viewing angle, which occurs uponassembly displacement between the CF glass substrate 13 and the TFTglass substrate 12 of a high definition panel, and the function oflessening the resistance of the common electrode wiring layer 14. Inthis case, the division position of the common electrode wiring layer 14is located above a not shown video line (gate wiring layer). Therefore,the metal wiring layers 15 may be disposed above the signal lines(source wiring layers) 16 in entirety except a part which intersects thegate wiring layer. In other words, the metal wiring layers 15 are formedabove the signal wiring layers 16, corresponding to the positions belowBMs 17 in entirety.

A CF glass substrate 13 includes color filters (color layer) 18 of red(R), green (G) and blue (B), and the BMs 17. The color filters 18 arerepeatedly disposed in the row direction (X direction) in the order ofR, G and B. The color filter 18 has the same color sections arranged inthe column direction. The color filter has a rectangular shape in planarview, having a length in the X direction shorter than the one in the Ydirection.

A not shown detection electrode wiring layer extends in the directionparallel to a source wiring layer 16 (Y direction), and is periodicallydisposed in the X direction on a back surface of the CF glass substrate13 (upper surface shown in the lower section of FIG. 1).

Each of the common electrode wiring layer 14 and a pixel electrodewiring layer 19 is made of a translucent metal layer, for example, ITO.Each of the metal wiring layer 15 and the source wiring layer 16 is madeof a light shielding metal layer.

FIG. 2A is a view showing structure of the display device according to asecond comparative example. FIG. 2B represents the color mixture whichoccurs on the display device according to the second comparativeexample. The upper section of FIG. 2A is a plan view showing a part ofthe liquid crystal display device, and the lower section is a sectionalview taken along line A-A′ of the upper section. Referring to a displaydevice 11A according to the second comparative example, the commonelectrode wiring layer 14 of the TFT glass substrate 12 extends in thedirection parallel to the source wiring layer 16 (Y direction), anddivided in the X direction so as to be periodically arranged. The metalwiring layers 15 are disposed in connection with the common electrodewiring layer 14 between the respective subpixels. In order to preventshort-circuit between the divided parts of the common electrode wiringlayer 14, the metal wiring layer 15 is not disposed at the divisionposition (division region) of the common electrode wiring layer 14. Inother words, the metal wiring layer 15 is not disposed above the sourcewiring layer 16 located at the division position of the common electrodewiring layer 14, which is located below the BM 17. As a result, colormixture at viewing angle may occur upon the assembly displacement(hereinafter simply referred to as “assembly displacement”) between theCF glass substrate 13 and the TFT glass substrate 12. The divisionregion (division position) 20 between the divided parts of the commonelectrode wiring layers 14 extends in the Y direction, and periodicallydisposed in the X direction. The division position 20 of the commonelectrode wiring layer 14 is interposed between the red subpixel and thegreen subpixel. The single divided part of the common electrode wiringlayer 14 includes 9 subpixels (3 pixels) arranged in the X direction.The distance (width of the division region) between the divided parts ofthe common electrode wiring layer 14 is smaller than the width of themetal wiring layer 15. The width of the metal wiring layer 15 is smallerthan that of the BM 17. The common electrode wiring layer 14 is notdivided in the Y direction, which is used for all the pixels arranged inthe Y direction.

FIGS. 3A to 3D are explanatory views with respect to the principle thatcolor mixture at viewing angle occurs upon assembly displacement. FIG.3A is a sectional view representing the state with no assemblydisplacement upon application of a white voltage only to the redsubpixels. FIG. 3B is a sectional view representing the state where theassembly displacement occurs upon application of the white voltage onlyto the red subpixels. The upper section of FIG. 3B is a sectional viewrepresenting the state where the CF glass substrate displaces to theright. The lower section of FIG. 3B is a sectional view representing thestate where the CF glass substrate displaces to the left. FIG. 3C is asectional view representing the state where the assembly displacementoccurs upon application of the white voltage only to the greensubpixels. The upper section of FIG. 3C is a sectional view representingthe state where the CF glass substrate displaces to the right. The lowersection of FIG. 3C is a sectional view representing the state where theCF glass substrate displaces to the left. FIG. 3D is a sectional viewrepresenting the state where the assembly displacement occurs uponapplication of the white voltage only to the blue subpixels. The uppersection of FIG. 3D is a sectional view representing the state where theCF glass substrate displaces to the right. The lower section of FIG. 3Dis a sectional view representing the state where the CF glass substratedisplaces to the left.

Referring to FIG. 3A, the white voltage is applied only to the redsubpixels, and no assembly displacement occurs. The boundary between thewhite voltage and the black voltage exists at the position correspondingto the center of the BM 17, which causes no color mixture at viewingpoint.

Referring to the upper section of FIG. 3B, the white voltage is appliedonly to the red subpixels. As the metal wiring layer 15 is disposed atthe position where the white voltage is near the adjacent blue colorfilter, if the white voltage is applied only to the red subpixels, andthe CF glass substrate 13 displaces to the right, no light leakageoccurs, neither the color mixture does. The condition represented by theupper section of FIG. 3B will be designated as “R+B” (which applies toFIG. 2B). Referring to the lower section of FIG. 3B, the white voltageis applied only to the red subpixels, and the CF glass substrate 13displaces to the left. The metal wiring layer 15 is not disposed at thepoint where the white voltage is near the adjacent green color filter.In this case, the light transmitting through the liquid crystal on theTFT glass substrate 12, corresponding to the red subpixel transmitsthrough the red and green color filters. This may cause the green to bemixed with the red. Meanwhile, no color mixture occurs at the pointwhere the metal wiring layer 15 is disposed at the boundary between thered and the green subpixels. The condition represented by the lowersection of FIG. 3B will be designated as “R+G” (which applies to FIG.2B).

Referring to the upper section of FIG. 3C, the white voltage is appliedonly to the green subpixels, and the CF glass substrate 13 displaces tothe right. The metal wiring layer 15 is not disposed at the point wherethe white voltage is near the adjacent red color filter. In this case,the light transmitting through the liquid crystal on the TFT glasssubstrate 12, corresponding to the green subpixel transmits through thegreen and the red color filters, resulting in the color mixture of redwith green. Meanwhile, the color mixture does not occur at the pointwhere the metal wiring layer 15 exists at the boundary between the greenand the red subpixels. The condition represented by the upper section ofFIG. 3C will be designated as “G+R” (which applies to FIG. 2B).Referring to the lower section of FIG. 3C, the white voltage is appliedonly to the green subpixels, and the CF glass substrate 13 displaces tothe left, the metal wiring layer 15 is disposed at the point where thewhite voltage is near the adjacent blue color filter. Therefore, nolight leakage occurs, neither the color mixture does. The conditionrepresented by the lower section of FIG. 3C will be designated as “G+B”(which applies to FIG. 2B).

Referring to the upper section of FIG. 3D, the white voltage is appliedonly to the blue subpixels, and the CF glass substrate 13 displaces tothe right. The metal wiring layer 15 is disposed at the point where thewhite voltage is near the adjacent green color filter. Therefore, nolight leakage occurs, neither the color mixture does. The conditionrepresented by the upper section of FIG. 3D will be designated as “B+G”(which applies to FIG. 2B). Referring to the lower section of FIG. 3D,the white voltage is applied only to the blue subpixels, and the CFglass substrate 13 displaces to the left. The metal wiring layer 15 isdisposed at the point where the white voltage is near the adjacent redcolor filter. Accordingly, no light leakage occurs, neither the colormixture does. The condition represented by the lower section of FIG. 3Dwill be designated as “B+R” (which applies to FIG. 2B).

If the division position of the common electrode wiring layer 14 islocated at the point between the red subpixel and the green subpixel,the color mixture at viewing angle occurs as described above. If thedivision position of the common electrode wiring layer 14 is located atthe point between the green subpixel and the blue subpixel, the colormixture of blue with the green, or green with the blue occurs. If thedivision position of the common electrode wiring layer 14 is located atthe point between the blue subpixel and the red subpixel, the colormixture of the red with the blue or the blue with the red occurs. Iflight leakage occurs at the subpixel with high transmittance, the colormixture becomes worsened. It is therefore preferable to avoid divisionof the common electrode wiring layer at the side of the subpixel withthe highest transmittance. Among the subpixels, the transmittance ishigh in the order of white subpixel>green subpixel>red subpixel>bluesubpixel. In other words, the white subpixel has the highesttransmittance, and the blue subpixel has the lowest transmittance.

Referring to FIG. 2B, the section A represents the state where the CFglass substrate displaces to the right, and the section B represents thestate where the CF glass substrate displaces to the left. Referring toFIG. 2B, states AR and BR represent the liquid crystal display deviceseen from the right side, and states AC and BC represent the liquidcrystal display device seen from the front. States Al and BL representthe liquid crystal display device seen from the left side. Referring toFIG. 2B, states A1 and B1 represent the display device resulting fromassembly displacement upon application of the white voltage only to thered subpixels, states A2 and B2 represent the display device resultingfrom assembly displacement which occurs upon application of the whitevoltage only to the green subpixels, and states A3 and B3 represent thedisplay device resulting from assembly displacement which occurs uponapplication of the white voltage only to the blue subpixels. Thedivision position of the common electrode wiring layer 14, that is, thepoint at which the metal wiring layer 15 is not disposed is periodicallyarranged. In the state defined by A2 and AR shown in FIG. 2B, redvertical stripes may appear in the condition G+R. In the state definedby B1 and BL, the green vertical stripes may appear on the red screen inthe condition R+G.

Embodiments and modified examples will be described referring to thedrawings. In the following description, the same elements are designatedwith the same codes, and explanations thereof, thus will be omitted.

FIGS. 4A and 4B illustrate structure of a liquid crystal display deviceaccording to a first embodiment. FIG. 4A is a plan view of therespective substrates of the liquid crystal display device, and FIG. 4Bis a side view. A liquid crystal display device 40 according to thefirst embodiment includes an in-cell type touch panel function, whichallows the common electrode wiring layer to function as the driveelectrode wiring layer of the touch panel.

The liquid crystal display device 40 includes the TFT glass substrate12, the CF glass substrate 13, the liquid crystal layer 21, a backlight41, a polarizing plate 42, a controller 43, a touch IC 45, and cables 49a, 49 b, 49 c. The liquid crystal display device 40 has a verticallylong structure (the length in the Y direction is longer than that in theX direction). The TFT glass substrate 12 includes an LCD scan circuit46, a common electrode selector (COM selector) 47, and a signal lineselector 48 in the form of TFT. A driver 44 formed as a semiconductorintegrated circuit (IC) such as CMOS is installed in the TFT glasssubstrate 12 through COG mounting. The driver 44 is connected to thecontroller 43 formed as the IC via the cable 49 a. A plurality ofdetection electrode wiring layers 50 extending in the X direction areformed on the upper surface (opposite the liquid crystal layer 21) ofthe CF glass substrate 13. The detection electrode wiring layers 50 areconnected to the touch IC 45 via the cable 49 b, which is mountedthereon. The cable 49 b is connected to the controller 43. The backlight41 is connected to the controller 43 via the cable 49 c. The polarizingplates 42 are disposed on the upper surface of the CF glass substrate13, and between the backlight 41 and the TFT glass substrate 12,respectively.

FIGS. 5A to 5C are views showing structure of the TFT glass substrateaccording to the first embodiment. FIG. 5A is a plan view illustrating apart of the TFT glass substrate, and FIG. 5C is a plan view showing apartially enlarged part of a region enclosed with a broken line shown inFIG. 5A. FIG. 5B is a sectional view taken along line B-B′ of FIG. 5C.

The common electrode wiring layer 14 extends parallel to the signalwiring layer 16 (in the Y direction), and is divided in the X directionso as to be periodically arranged. The metal wiring layer 15 is disposedbetween the respective subpixels, which is in connection with the commonelectrode wiring layer 14. In order to prevent short-circuit between thedivided parts of the common electrode wiring layer 14, the metal wiringlayer 15 is not disposed at the division position (in the divisionregion) of the common electrode wiring layer 14. In other words, themetal wiring layer 15 is not disposed above the signal wiring layer 16located at the division position of the common electrode wiring layer14, corresponding to the position below the BM 17. The division region(division position) 20 between the divided parts of the common electrodewiring layer 14 extends in the Y direction, and periodically arranged inthe X direction. The metal wiring layer 15 is not disposed between thesame colors as those at the division position of the divided parts ofthe common electrode wiring layer 14. Except contact holes forconnecting the pixel electrode layer 19 and a drain electrode layer 56,the divided parts of the common electrode layer 14 are connected betweenthe subpixels. For convenience of graphic representation, the singledivided part of the common electrode wiring layer 14 in the X directioncontains 6 subpixels (2 pixels). In this embodiment, likewise the secondcomparative example as shown in FIG. 6A, the single divided part of thecommon electrode wiring layer 14 in the X direction contains 9 subpixels(3 pixels). The distance between the divided parts of the commonelectrode wiring layer 14 (width of the division region) is smaller thanthat of the metal wiring layer 15. The metal wiring layer 15 has thewidth smaller than that of the BM 17.

A gate wiring layer 51 is formed on a glass substrate 58, on which asemiconductor layer 53 is formed via a gate insulating film 52. Thesource wiring layer 16 and the drain electrode layer 56 are connected tothe semiconductor layer 53 via the contact hole of an inter-layerinsulating layer 54. The common electrode wiring layer 14 is disposedabove the source wiring layer 16 via an insulating film layer 55. Themetal wiring layer 15 is disposed on the common electrode wiring layer14 in contact therewith at the position above the source wiring layer16. The pixel electrode layer 19 is formed on the common electrodewiring layer 14 via an inter-layer insulating film layer 57. The pixelelectrode layer 19 is connected to the drain electrode layer 56 via thecontact hole of the insulating film layer 55. The pixel electrode layer19 has a slit. The gate wiring layer 51 extends in the X direction, andalso extends in the Y direction towards the semiconductor layer 53. Thecommon electrode wiring layer 14 and the pixel electrode layer 19 aremade of the translucent metal layer such as ITO. Meanwhile, the metalwiring layer 15 and the source wiring layer 16 are made of the lightshielding metal layer.

FIG. 6A is a view illustrating structure of the liquid crystal displaydevice according to the first embodiment. FIG. 6B represents the colormixture on the liquid crystal display device according to a thirdcomparative example. The upper section of FIG. 6A is a plan viewillustrating a part of the liquid crystal display device, and the lowersection is a sectional view taken along line A-A′ of the upper section.The display device 40 according to the first embodiment has the similarstructure to that of the display device 11A according to the secondcomparative example. The metal wiring layers 15 are not disposed atpositions between the subpixels of the same color as those at thedivision position of the common electrode wiring layer 14. The displaydevice 11A according to the second comparative example is configuredthat the common electrode wiring layer 14 is divided at the positionbetween the red and the green subpixels. Meanwhile, the display device40 according to the first embodiment is configured that the commonelectrode wiring layer 14 is divided between the red and the bluesubpixels. Referring to FIG. 6A, the common electrode wiring layer 14 isdivided between the red and the blue subpixels at which the metal wiringlayers 15 is not disposed at all. Likewise the second comparativeexample, the liquid crystal display device according to the thirdcomparative example is configured that the common electrode wiring layer14 is divided between the red and the green subpixels at which the metalwiring layer 15 is not disposed at all.

The color mixture that occurs in the liquid crystal display deviceaccording to the third comparative example will be described. Referringto FIG. 6B, the section A represents the state where the CF glasssubstrate displaces to the right, and the section B represents the statewhere the CF glass substrate displaces to the left. Referring to FIG.6B, the states AR and BR represent the liquid crystal display deviceseen from the right side, the states AC and BC represent the liquidcrystal display device seen from the front, and states AL and BLrepresent the liquid crystal display device seen from the left side.Referring to FIG. 6B, states A1 and B1 represent the display deviceresulting from assembly displacement which occurs upon application ofthe white voltage only to the red subpixels, states A2 and B2 representthe display device resulting from assembly displacement which occursupon application of the white voltage only to the green subpixels, andstates A3 and B3 represent the display device resulting from theassembly displacement which occurs upon application of the white voltageonly to the blue subpixels. The division positions of the commonelectrode wiring layer 14, that is, the parts with no metal wiringlayers 15 are arranged periodically at shorter cycle than the secondcomparative example. In the state defined by A2 and AR in the conditionG+R shown in FIG. 6B, the red is uniformly mixed with the green screento a small extent. In the state defined by B1 and BL in the conditionR+G, the green is uniformly mixed with the red screen to a small extent.

The color mixture on the display device according to the firstembodiment will be described. As the metal wiring layers 15 areeliminated from all the regions between the red and the blue subpixelsin the display device 40, in the state defined by B3 and BL in thecondition B+R shown in FIG. 6B, the red is uniformly mixed with the bluescreen to a small extent. In the state defined by A1 and AR in thecondition R+B, the blue is uniformly mixed with the red screen to asmall extent. The metal wiring layers 15 are retained at the side of thegreen subpixel with the highest transmittance. Therefore, compared tothe third comparative example (shown in FIG. 6B), this case ensures toprevent the color mixture with higher possibility.

It has been clarified that the above-structured embodiment fails toprovide the effect for preventing the color mixture at viewing angle atthe point between the red and the blue subpixels, but provides sucheffect at the points between the red and the blue, and between the greenand the red.

The common electrode wiring layer 14 functioning as the drive electrodewiring layer of the touch panel extends in the Y direction, and dividedin the X direction so as to be periodically arranged. A plurality ofdetection electrode wiring layers 50 extend in the X direction, andarranged in the Y direction. The width of the common electrode wiringlayer 14 is larger than that of the detection electrode wiring layer 50.The detection electrode wiring layer can be increased more easily thanthe common electrode wiring layer. It is therefore possible for thevertically long display device to improve the touch detection accuracyeasily by increasing the number of the detection electrode wiringlayers.

Second Embodiment

The liquid crystal display device according to the second embodiment hasthe same structure as that of the liquid crystal display device 11Aaccording to the second comparative example shown in FIG. 2A. That is,it is configured not to dispose the metal wiring layers 15 only at thedivision position, and to arrange them at the point between thesubpixels. If the definition of the subpixel is sufficient, the width ofthe region where color mixture at viewing angle occurs between thesubpixels only in plane may be sufficiently small so that the colormixture cannot be visually recognized by the observer. Therefore, thismakes it possible to provide the effect for preventing the color mixturebetween the red and the green subpixels. Division of the commonelectrode wiring layer 14 at the point between the red and the bluesubpixels may further provide the effect of preventing the colormixture.

Third Embodiment

FIG. 7A is a view illustrating structure of the liquid crystal displaydevice according to a third embodiment. FIG. 7B represents the colormixture on the liquid crystal display device according to the thirdembodiment. The upper section of FIG. 7A is a plan view showing a partof the liquid crystal display device, and the lower section of FIG. 7Ais a sectional view taken along line A-A′ of the upper section. A liquidcrystal display device 40A according to the third embodiment isconfigured to have the division positions of the common electrode wiringlayer 14 formed into a zigzag shape.

The common electrode wiring layer 14 is divided in the direction of thesource wiring layer 16 (Y direction) so that it is divided at the pointbetween the red and the green subpixels on the first line L1, it isdivided at the point between the green and the blue subpixels on thesecond line L2, it is divided at the point between the blue and the redsubpixels on the third line L3, it is divided at the point between thegreen and the blue subpixels on the fourth line L4, and it is divided atthe point between the red and the green subpixels on the fifth line L5.The common electrode wiring layer 14 is divided in the direction of thegate wiring layer (X direction) so as to be located at the pointsbetween the green subpixel on the first line L1 and the green subpixelon the second line L2, the blue subpixel on the second line L2 and theblue subpixel on the third line L3, the blue subpixel on the third lineL3 and the blue subpixel on the fourth line L4, and the green subpixelon the fourth line L4 and the green subpixel on the fifth line L5,respectively. The division region 20 is formed to have the zigzag shapehaving the width corresponding to 2 subpixels in the X directionmicroscopically, and extends along the Y direction macroscopically.

Referring to FIG. 7A, the division regions of the common electrodewiring layer 14 in the direction of the gate wiring layer (X direction)are located at the upper part of the green subpixel on the first line L1and at the lower part of the green subpixel on the fifth line L5,respectively. The division region 20 of the common electrode wiringlayer 14 may be located at the upper part of the red subpixels on thefirst line L1, and at the lower part of the red subpixel on the fifthline L5 in the gate wiring layer direction (X direction). In such acase, the division region 20 is formed to have the zigzag shape havingthe width corresponding to 4 subpixels in the X directionmicroscopically, and extends along the Y direction macroscopically.

Referring to FIG. 7B, the section A represents the state where the CFglass substrate displaces to the right, and the section B represents thestate where the CF glass substrate displaces to the left. Referring toFIG. 7B, the states AR and BR represent the liquid crystal displaydevice seen from the right side, the states AC and BC represent theliquid crystal display device seen from the front, and the states AL andBL represent the liquid crystal display device seen from the left.Referring to FIG. 7B, the states A1 and B1 represent the display deviceresulting from assembly displacement upon application of the whitevoltage only to the red subpixels, the states A2 and B2 represent thedisplay device resulting from assembly displacement upon application ofthe white voltage only to the green subpixels, and the states A3 and B3represent the display device resulting from assembly displacement uponapplication of the white voltage only to the blue subpixels. If thedefinition of the structure shown in the second embodiment isinsufficient (second comparative example), there may be the cases wherethe part of the color mixture at viewing angle appears to be linearlyshaped. In such a case, the division positions are formed to have thezigzag shape likewise this embodiment. Then the blue vertical stripesappear on the red screen in the condition R+B in the state defined bythe A1 and AR. In the state defined by A2 and AR, the red verticalstripes appear on the green screen in the condition G+R. In the statedefined by A3 and AR, the green vertical stripes appear on the bluescreen in the condition B+G. Referring to FIG. 7B, in the state definedby B1 and BL, the green vertical stripes appear on the red screen in thecondition R+G, and in the state defined by B2 and BL, the blue verticalstripes appear on the green screen in the condition G+B. In the statedefined by B3 and BL, the red vertical stripes appear on the blue screenin the condition B+R. The division positions are formed to have thezigzag shape like the embodiment to enable the amount of light leakageupon the color mixture at viewing angle to be reduced to ⅓ of the one inthe second comparative example. Accordingly, visibility of the part ofthe color mixture at viewing angle may be made lower than that of thesecond comparative example.

Modified Example

FIG. 8 is a view illustrating structure of the liquid crystal displaydevice according to a modified example. The upper section of FIG. 8 is aplan view showing a part of the liquid crystal display device, and thelower section is a sectional view taken along line A-A′ of the uppersection. A liquid crystal display device 40B according to the modifiedexample forms the zigzag shape repeatedly arranged in one direction sothat the diagonally divided common electrodes are arranged. Theaforementioned configuration may be made for the purpose of lesseningvisibility of the color mixture at viewing angle.

The division position of the common electrode wiring layer 14 of theliquid crystal display device 40B is the same as that of the commonelectrode wiring layer 14 according to the third embodiment from thefirst line L1 to the third line L3. The division position of the commonelectrode wiring layer 14 of the liquid crystal display device 40B inthe Y direction is located between the red and the green subpixels onthe fourth line L4, and between the green and the blue subpixels on thefifth line L5, for example. The division position of the commonelectrode wiring layer 14 in the X direction is located between the redsubpixel on the third line L3 and the red subpixel on the fourth lineL4, and between the green subpixel on the fourth line L4 and the greensubpixel on the fifth line L5. The division regions 20 are arranged toform the zigzag shape microscopically, and extends along the Y directionmacroscopically.

Fourth Embodiment

FIG. 9A is a view illustrating structure of the liquid crystal displaydevice according to a fourth embodiment. FIG. 9B is a view representingthe color mixture on the liquid crystal display device according to thefourth embodiment. Referring to FIG. 9A, the upper section is a planview showing a part of the liquid crystal display device and the lowersection is a sectional view taken along line A-A′ of the upper section.A display device 40C according to the fourth embodiment is configured toreplace half the blue subpixels with white subpixels in addition to thethree-color subpixels of RGB. The display device 40C according to thefourth embodiment is configured to have four-color subpixels of RGBW,which allows both the blue subpixels and the white subpixels to use thesame source wiring layer 16, and the division position of the commonelectrode wiring layer 14 in the direction of the source wiring layer 16(Y direction) to form the zigzag shape passing between the red subpixeland the blue subpixel. The division position of the common electrodewiring layer 14 in the direction of the source wiring layer 16 is notlocated between the white subpixel and the blue subpixel. The divisionpositions of the common electrode wiring layer 14 in the direction ofthe gate wiring layer (X direction) are located at points between thewhite subpixel on the first line L1 and the blue subpixel on the secondline L2, the blue subpixel on the second line L2 and the white subpixelon the third line L3, the white subpixel on the third line L3 and theblue subpixel on the fourth line, and the blue subpixel on the fourthline L4 and the white subpixel on the fifth line L5. The division region20 is formed to have the zigzag shape having the width corresponding to3 subpixels in the X direction microscopically, and extends along the Ydirection macroscopically. The single divided part of the commonelectrode wiring layer 14 includes 12 subpixels (4 pixels) in the Xdirection.

Referring to FIG. 9B, the section A represents the state where the CFglass substrate displaces to the right, and the section B represents thestate where the CF glass substrate displaces to the left. The states ARand BR represent the liquid crystal display device seen from the rightside, the states AC and BC represent the liquid crystal display deviceseen from the front, and the states AL and BL represent the liquidcrystal display device seen from the left side. The states A1 and B1represent the display device resulting from assembly displacement uponapplication of the white voltage only to the red subpixxels, the statesA2 and B2 represent the display device resulting from assemblydisplacement upon application of the white voltage only to the greensubpixels, and the states A3 and B3 represent the display deviceresulting from assembly displacement upon application of the whitevoltage only to the blue subpixels. Referring to FIG. 9B, in the statedefined by A1 and AR, the blue vertical stripes appear on the red screenin the condition R+B. In the state defined by B3 and BL, the redvertical stripes appear on the blue screen in the condition B+R. Thedivision positions are arranged to form the zigzag shape like thisembodiment, which makes it possible to reduce the light leakage amountresulting from the color mixture at viewing angle to be smaller than thesecond comparative example by ½. Accordingly, it is possible to lessenthe visibility of the color mixture part at viewing angle compared withthe second comparative example.

Preferably, the common electrode wiring layer 14 is divided at the pointlocated between the red and the blue subpixels where the leakage oflight, if any, is unlikely to be recognized as the color mixture becauseof small amount of transmitted light. Assuming that the pixel structureincludes the four-color subpixels of RGBW, allowing the blue and whitesubpixels to use the same source wiring layer 16, the linear division ofthe common electrode wiring layer between the red and the blue subpixelsmay contain the side part of the white subpixels with hightransmittance. When the common electrode wiring layer 14 is divided atthe side of the white subpixel with higher transmittance than the greensubpixel, the color mixture at viewing angle markedly appears if thelight leaks. The division may be made at the point between the red andthe blue subpixels to form the zigzag shape so as to avoid the whitesubpixel, resulting in the lessened color mixture at viewing angle. Ifthe common electrode wiring layer 14 is linearly divided likewise thesecond comparative example, it is preferable to perform the division atthe point between the red and the green subpixels likewise the secondcomparative example for avoiding the side part of the white subpixel.

Having been described with respect to the present invention by theapplicant in reference to the embodiments, examples and modifiedexample, the present invention is not limited to those embodiments andthe modified examples, which can be modified in various manners.

What is claimed is:
 1. A display device including a plurality of firstpixels, comprising: a first substrate; and a second substrate, whereinthe first substrate includes a gate wiring extending in a firstdirection, a plurality of source wirings arranged in the firstdirection, each extending in a second direction that is different fromthe first direction, a common electrode extending in the seconddirection, which is separated into a plurality of parts each with apredetermined pixel width in the first direction, and a plurality ofmetal wirings arranged in the first direction, each extending in thesecond direction; each of the first pixels includes a first colorsubpixel, a second color subpixel, and a third color subpixel, which arearranged in a sequence along the first direction; the source wiringsinclude a first wiring and a plurality of second wirings which arepositioned at both sides of the first wiring; a separation region of thecommon electrode is positioned between the first color subpixel and thesecond color subpixel, which is located at a part above the firstwiring, the metal wiring is disposed on the common electrode in contacttherewith and is disposed above a part of the second wirings, the commonelectrode is a transparent conductive film, and the metal wiring is alight shielding conductive film.
 2. The display device according toclaim 1, wherein the division region has a rectangular shape in planarview, extending in the second direction, and a width smaller than thatof the metal wiring.
 3. The display device according to claim 1, whereina distance between adjacent metal wirings which interpose the firstcolor and the second color subpixels is larger than the distancesbetween adjacent metal wirings which interpose the second color and thethird color subpixels, and the distance between adjacent metal wiringswhich interpose the third color and the first color subpixels.
 4. Thedisplay device according to claim 1, wherein a part of the commonelectrode, having a first pixel line disposed in the first direction isdivided to locate a division region at a position between the firstcolor and the second color subpixels at intervals of predeterminednumbers of the subpixels; a part of the common electrode, having asecond pixel line disposed in the first direction adjacent to the firstpixel line is divided to locate the division region at a positionbetween the second color and the third color subpixels at intervals ofpredetermined numbers of the subpixels; a part of the common electrode,having a third pixel line disposed in the first direction adjacent tothe second pixel line is divided to locate the division region at aposition between the third color and the first color subpixels atintervals of predetermined numbers of the subpixels; a part of thecommon electrode, having a fourth pixel line disposed in the firstdirection adjacent to the third pixel line is divided to locate thedivision region at a position between the second color and the thirdcolor subpixels at intervals of predetermined numbers of the subpixels;a part of the common electrode, having a fifth pixel line disposed inthe first direction adjacent to the fourth pixel line is divided tolocate the division region at a position between the first color and thesecond color subpixels at intervals of predetermined numbers of thesubpixels, and the division region has a shape in planar viewmacroscopically as a straight line extending in the second direction,and microscopically as a zigzag line extending in the first and thesecond directions.
 5. The display device according to claim 1, wherein apart of the common electrode, having a first pixel line disposed in thefirst direction is divided to locate the division region at a positionbetween the first color and the second color subpixels at intervals ofpredetermined numbers of the subpixels; a part of the common electrode,having a second pixel line disposed in the first direction adjacent tothe first pixel line is divided to locate the division region at aposition between the second color and the third color subpixels atintervals of predetermined numbers of the subpixels; a part of thecommon electrode, having a third pixel line disposed in the firstdirection adjacent to the second pixel line is divided to locate thedivision region at a position between the third color and the firstcolor subpixels at intervals of predetermined numbers of the subpixels;a part of the common electrode, having a fourth pixel line disposed inthe first direction adjacent to the third pixel line is divided tolocate the division region at a position between the first color and thesecond color subpixels at intervals of predetermined numbers of thesubpixels; a part of the common electrode, having a fifth pixel linedisposed in the first direction adjacent to the fourth pixel line isdivided to locate the division region at a position between the secondcolor and the third color subpixels at intervals of predeterminednumbers of the subpixels, and the division region has a shape in planarview macroscopically as a straight line extending in an obliquedirection, and microscopically as a zigzag line extending in the firstand the second directions.
 6. The display device according to claim 1,wherein the second substrate includes a detection electrode wiring whichextends in the first direction, and the common electrode functions as adrive electrode wiring of an in-cell type touch panel.
 7. The displaydevice according to claim 1, wherein the second substrate includes afirst color layer, a second color layer and a third color layercorresponding to the subpixels of the first color, the second color andthe third color, and black matrices each interposed between therespective layers of the first, the second and the third color layers.8. The display device according to claim 1, wherein the first color isblue, the second color is red, and the third color is green.
 9. Adisplay device including a plurality of pixels, comprising: a firstsubstrate; a second substrate; and a liquid crystal layer interposedbetween the first and the second substrates, wherein each of the pixelsincludes a first subpixel, a second subpixel and a third subpixel whichare arranged in a sequence along a first direction; the first, thesecond and the third subpixels are disposed at a plurality of positionsin a second direction different from the first direction; the firstsubstrate includes a source wiring extending in the second direction, acommon electrode extending in the second direction, which is separatedinto parts each having a predetermined length in the first direction,and a metal wiring layer extending in the second direction; the secondsubstrate includes a first detection electrode; the common electrode isa transparent conductive film; the metal wiring is a light shieldingconductive film; the common electrode is used for pixels in commondisposed at a plurality of positions in the second direction; the commonelectrode functions as a second detection electrode; a separation regionof the common electrode is disposed on the source wiring between thefirst and the second subpixels; and the metal wiring is disposed on thecommon electrode above the source wiring.
 10. The display deviceaccording to claim 9, wherein the first, the second and the thirdsubpixels are arranged at a plurality of positions in the seconddirection, and the separation regions each having a rectangular shape inplanar view extending in the second direction are located at a pluralityof positions between the first and the second subpixels.
 11. The displaydevice according to claim 10, wherein a distance between adjacent metalwirings which interpose the separation region is larger than thedistance between other adjacent metal wiring.
 12. The display deviceaccording to claim 10, wherein a distance between the metal wiringpositioned between the third and the first subpixels and the metalwiring positioned between the second and the third subpixels is largerthan the distance between the metal wiring positioned between the secondand the third subpixels and the metal wiring positioned between thethird and the first subpixels.
 13. The display device according to claim9, wherein the second substrate includes a first color layer, a secondcolor layer and a third color layer corresponding to the first, thesecond, and the third subpixels, and black matrices each interposedbetween the respective layers of the first, the second, and the thirdcolor layers.
 14. The display device according to claim 9, wherein thefirst subpixel is blue, the second subpixel is red and the thirdsubpixel is green.